How to Build a Plastic Model

By Dave Johnson

Your first plastic model was probably a disappointing amalgam of gluey fingerprints, unrealistic blobs of paint, bumpy decals, and poorly joined parts. The good news is that model building is a skill that improves with practice. Here are some pointers to get you started down the road to modeling perfection.

How to Build a Plastic Model

Things You Will Need

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Clothespins or clamps

Cyanoacrylate instant glue

Modeling blade

Emery board

Paint

Paint brush

Paint thinner

Plastic modeling cement

Rags or paper towels

Rubber bands

Sandpaper

Tweezers

Getting Ready

Set up a dedicated modeling space. Any desk or table will work, but an inexpensive drafting table is perfect – it’s a good size for modeling and you can angle the surface so it’s more comfortable. Make sure there’s good ventilation, since you’ll work with glue and paint, and a bright, movable lamp you can position over the action. Cover the surface with newspaper to protect the tabletop, and do most of your work on a wooden cutting board you don’t mind subjecting to cuts, glue drips or paint spills.

Gather the necessary tools. The bare essentials to get started with plastic models include a modeling blade for cutting parts from the sprue (the sheet all the parts connect to), an emery board to smooth rough edges, and plastic modeling cement. For detail work, invest in some sandpaper. Sandpaper comes in many grades: The lower the number, the more coarse the grit. Plastic models generally benefit from sandpaper rated 200 - 400. A rag and paper towels are also handy. Please see the last slide for an itemized list of tools and materials.

Consider other tools that make modeling much more fun and convenient. You’ll find it handy to have a pair of tweezers or needle-nosed pliers, as well as a small clamp stand to hold tiny pieces in place, not to mention rubber bands and some spring-loaded clothespins. Model stores often sell very nice stands with a pair of articulated alligator clips for precisely positioning small parts. Instant glue (cyanoacrylate) is a great supplement to plastic cement as well.

Invest in a few brushes, paint, thinner, and spare paint jars (to mix paints and clean your brush). Truly professional-looking models are generally spray painted (often with the help of an inexpensive air compressor and air brush) rather than hand painted with a brush.

Familiarize yourself with the instructions and look over the various sprues. Get a feel for which parts you’ll need to paint first, before the model is assembled, and which parts should be painted toward the end, after major assembly is complete. That way you won’t accidentally miss painting parts that will be hard to reach after assembly. Also look for any moving parts that won’t be glued. Review which parts are on which sprues, so everything is easier to locate when you need it.

Assembling the Model

Follow the directions – assemble the model in the specified sequence.

Detach parts from the sprue only as you need them, carefully slicing them away with a modeling blade, rather than with scissors or wire cutters. After removing each piece, use an emery board to smooth away burrs left behind. In many cases, you might find it helpful to paint these parts before removing them from the sprue, but be sure to touch up the spot where it was cut away afterwards. Some modelers wash parts in a mild detergent after removing them, though this isn’t essential. To keep from losing small parts, you might keep a mug or cup on your modeling table to store detached pieces.

Strive to use the smallest amount of glue needed to bond parts together, and apply it carefully so none spills onto the visible surface of a part. When pre-painting parts, don’t paint the surfaces where you’ll be gluing. If you make a mistake, sand the paint away with sandpaper or an emery board.

After gluing parts together, let them rest until they’re completely dry – several hours, unless you use instant cyanoacrylate glue, which is completely cured in just a minute or so. Clamps, rubber bands, and similar tools can help hold parts together while they dry, but don’t apply too much pressure. Overstressing a plastic model with too many rubber bands can distort the plastic and cause gaps along the seams.

Use instant glue to quickly set two small pieces together with only one or two dabs of glue. Choose plastic cement for large surfaces or areas that require more structural integrity. Instant glue, for example, will start to set before you can align the parts if you have to apply it to too many places. There’s also a place for white glue in plastic modeling: It’s great for clear plastic parts, like airplane canopies and car headlights.

Work on different sections of a model simultaneously, so you can build a major subassembly while the glue or paint on another section dries.

Repair gaps or imperfections by applying a little plastic modeling putty, letting it cure completely, and then sanding it smooth. Be careful, though: This is a somewhat more advanced technique and you should practice on a part of the model that no one will see, like the inside of the hull, fuselage, or chassis. If you’re too aggressive with the sandpaper, you might roughen what should be a smooth exterior surface, or you might sand away finely etched details. You’ll also want to paint any surface you’ve filled with putty. For the best results, apply multiple coats of paint or start with a white or grey base coat and then paint the final color on top. This ensures that you won’t see the color difference between the putty and the surrounding plastic.

Painting the Model

Paint small details with a brush. Be sure to choose a brush size appropriate to the scale of the part; it’s helpful to have a collection of brushes that span a range of sizes.

Apply the paint in layers. You’ll get a much better result by applying a thin coat of paint, waiting for it to dry, and then adding another coat than by trying to slather on a thick coating of paint all at once. Lighter colors generally take more coats than darker colors to get good, solid coverage, and it’s not out of the question for it to take six or more coats to cover plastic with white. Be patient and keep applying light coats – it definitely will be worth the time.

Clean the brushes thoroughly in thinner designed for the kind of paint you’re using. Acrylic paint – increasingly popular for plastic models – can be cleaned with soapy water.

Beginning modelers often feel more comfortable with a brush, though as you gain experience, you might want to try spray paint, which can give a more consistent and professional appearance. You can use cans of spray paint, but for greater control and visual quality, consider an air compressor and air brush. Among other advantages, you can mix paints to get precise colors.

Control where you’re painting by applying modeling tape. If you’re painting a hull that has two contrasting colors, for example, use tape to lay down a line for the first color (always paint the lighter color first). To save on the cost of (relatively) expensive modeling tape, use the tape to create the actual paint seam. Then use cheaper masking tape to protect the rest of the model with newspaper or similar paper.

Experiment as you get more familiar with spray painting. For example, you can paint camouflage patterns without applying tape – by “feathering” sections of color over each other so they lightly overlap, you’ll get a more realistic effect.

Applying Decals

Applying decals is generally the last thing you do to a model, though there are some decals you might need to apply during construction because that part of the assembly will be inaccessible later.

Read the directions for applying decals; the process can vary. But in general, you’ll want to carefully cut the decal off the sheet (you can use a blade or quality, sharp scissors) and submerge it in warm water for about 30 seconds.

Test the decal gently. If it starts to slide off the backing, it’s ready. Position it near the model surface and slide it into place. When it’s in position, dab the decal very gently with a ball of cotton or a tissue to blot out the water and flatten the decal. Don’t fiddle with the decal too much or it might tear. If you need to reposition a decal that has started to adhere to the model (but is not complete set), apply a little water to soften its glue.

Tip

If you use an air brush, be sure to spray paint thinner through the mechanism when you’re done with each color to prevent gumming the nozzle and other parts with dried paint.

Things You Will Need

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Clothespins or clamps

Cyanoacrylate instant glue

Modeling blade

Emery board

Paint

Paint brush

Paint thinner

Plastic modeling cement

Rags or paper towels

Rubber bands

Sandpaper

Tweezers

Tip

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If you use an air brush, be sure to spray paint thinner through the mechanism when you’re done with each color to prevent gumming the nozzle and other parts with dried paint.

About the Author

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Dave Johnson is editor of eHow's Tech channel, and the author of about 3 dozen books, including the best-selling, "How to Do Everything with Your Digital Camera." He has appeared in dozens of magazines and websites, including PC World, Wired, and CBS MoneyWatch.